It's essential that startup teams have great chemistry.

If you don't appreciate their sense of humor (or vice versa), it's probably not a good fit. That's fine.

It's better to establish these things sooner versus later in the interview process, so you're not wasting each other's time.

To this end, I think it's productive when startups post job listings like this that genuinely reflect their culture and personality. It can serve as the first of several mutual filters to weed out potential candidates who wouldn't work well with the team.